GOING FOR
THE HAT TRICK Higgins’ trio of Hamm 3412 compactors
The big Wirtgen WR240 soil stabiliser in action
Higgins’ Streumaster SW 16 MC spreader is the first of its kind in NZ
A multifaceted civil construction project needs a multifaceted approach to construction hardware; especially when the work site extends for 18km. That’s exactly the approach that Wirtgen New Zealand has been able to take in conjunction with M2PP Alliance partner, Higgins. THE COMPLEX WORKING environment of the 18km-long MacKays to Peka Peka (M2PP) Expressway site – a component of the Wellington Northern Corridor Roads of National Significance project – is split into three zones; northern, central and southern. This means there are multiple work fronts all progressing in unison, with Wirtgen New Zealand-supplied equipment being relied upon each step of the way. “It’s a complex site with a lot going on. All the gear you see is here for a reason; we need it to work hard and consistently for us, and that’s why we trust it,” says M2PP pavements manager Jonathan Kibblewhite. “Higgins and Wirtgen New Zealand have enjoyed a long working relationship.” That relationship extends to utilising leading technology never before trialled in New Zealand, such as Higgins’ truck-mounted Streumaster SW 16 MC binding agent spreader unit. It’s no small matter bringing brand new technology onto a complex work site like M2PP, where each crew involved is an integral component of a critical path; wholly reliant on the speed and efficiency of the other 16 www.contractormag.co.nz
crews surrounding and supporting them. “From 7.00am until 10.00am we’re spreading 75 tonnes of cement and hoeing it in three hours,” says Jonathan. “Our teams are incredibly efficient, so we need to know the mobile plant we’re bringing in has the ability to keep up with the required work flow. The Streumaster is very quick though; what’s more the standard software onboard gives our guys absolute accuracy through load cell monitoring.” Operator John Burrows says the improvements in speed and consistency the Streumaster SW 16 MC offers are second-to-none. “It’s an impressive machine. It’s about four times as fast as the previous spreader I used. Because it features a moving chain-driven conveyor floor, this really helps with the consistency of the spread,” says John. “It’s intuitive to use and gives you very good width control through the gates. You can isolate each gate and run it individually, or run all three at the same time; this means you have a lot of flexibility with the spread width – from a 2.5m maximum to a one metre minimum.”
John says that, whereas older style gates often let extra product slide through, the Streumaster system is very precise. Mounted to a Hino chassis, the Higgins spreader unit holds a maximum of 16 tonnes of cement and fully loaded weighs around 26 tonnes. The unit features a self-cleaning mode and a spreading quantity of between five and 35-litres/min² at around 2km/h. “What we previously needed to do in two runs, we can now complete in one thanks to the Streumaster’s heavy application rate. This improved application rate means we can use the machine more efficiently on site,” adds Jonathan Kibblewhite. A relatively recent addition to the Wirtgen Group umbrella of construction equipment, the Streumaster is just one of three brands supplied by Wirtgen New Zealand working the soil along this section of what will eventually be the four-lane M2PP expressway. Joining the binding agent spreader is a large capacity Wirtgen WR240 soil stabiliser, along with a fleet of three Hamm 3412 compactors. As a result of its large working width and depth and solid milling and mixing performance, the Wirtgen WR240 provides the Higgins team with ample power, all-terrain surefootedness and flexibility for soil stabilisation or cold recycling. And with approximately 800,000m² of stabilising required along the 18km expressway, the Hawke’s Bay-based stabilisation crew are well-versed in getting great results.
Jonathan explains that while the Wirtgen WR240 will be used on both the expressway and local roads, the expressway’s design is quite unique. “There is 210mm of sub-base and we stabilise 185mm. The reason for this is that we want to keep a consistent 25mm buffer so that when we’re stabilising, we don’t accidentally pick up the sand underneath and drag it into the pavement layer. It’s almost like a sacrificial layer if you like. “We then put on 175mm of base course and stabilise that; we’re knitting the top of the sub-base layer, so we’re stabilising at 180mm rather than 175mm.” A familiar site on Higgins’ many infrastructure projects around the country, Hamm compactor technology is also present at the M2PP site, with three Hamm 3412 machines working; two boasting standard vibratory drums and one a pad foot. “We’ve definitely had a long relationship with Hamm,” says Jonathan. “I remember our smaller Hamm HD14s joining the fleet five or six years ago. Since then the technology and capability of these machines has just gotten better and better.” While Jonathan is an old hand, operator Steven Keys is new to Hamm machines, but says he’s very happy with his ‘company vehicle’. “I’ve been operating one for about six months and it’s really good. The cab offers great visibility, the controls are all really well laidout and the compaction is strong; you never feel like the machine is struggling.” All three of Higgins’ compactors are also wired up for Hamm’s modular compaction measuring, documenting and analysing system known as Hamm Compaction Quality (HCQ). The HCQ system consists of a ruggedised in-cab panel PC with a touchscreen interface connected to a Differential Global Positioning System (DGPS) receiver. The HCQ system receives satellite signals along with a DGPS correction signal, meaning the software remains connected even when compacting under bridges or in locations with radio shadowing. The completely portable system identifies the machine it is connected with and will then give the operator crucial real-time data on the go, including compaction stiffness measurements and maps of compaction levels and how many passes have been made. This means the operator can watch the progress of the compaction in real-time and react accordingly. Collected data is then downloadable onto USB, ready for the Higgins team to analyse back at base, or take onboard another of the Hamm 3412s’ onsite as a reference guide for the next operator. Jonathan says that Higgins also plans to overlay surface design data onscreen, so every operator can quickly see where they are in relationship to the actual design. And there’s yet more Hamm technology that Jonathan says could certainly have an application along certain sections of the M2PP project site too. “We’re unable to use straight vibration on sand so close to residential dwellings along some sections of the project. This means that in the near future there might be an opportunity to use Hamm’s oscillation technology instead, where the compaction energy is introduced both vertically and horizontally at the same time, rather than straight down as is traditional. “In the meantime, our Hamm 3412 compactors are certainly putting in the hard yards in the consistent fashion we’ve come to expect from this brand,” he concludes. “That combination of reliability and technology allows our teams to get on with the job quickly and accurately, which is invaluable on such a complex project.” l • Words & photography supplied. APRIL 2015 17
PHOTOS: WIRTGEN NEW ZEALAND + HIGGINS @ M2PP FOR CONTRACTOR
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